Custom Ford F150 Prerunner Truck - Coming Full CirclePosted in Features on November 1, 2006 Comment (0)
Cash in hand and F-150 parked outside, Stu Ackley approached Tom McKenzie, dripping with anticipation. "I'd like to have a four-link put on this truck," he requested.
Tom sauntered over to Stu's newly purchased prize, which had already been the recipient of some metallic surgery. Tom did a cursory review of the truck. From a fabricator's viewpoint, it wasn't a pretty sight. The MIG wire protruding randomly through the roof was just one of the suspect items he saw. Tom broke the news: "I can't put a four-link on for you. This truck isn't safe."
Undeterred, Stu prodded, "Well, what can you do with this truck?"
Tom's verdict? "I can probably save the doors."
Longtime Off-Road readers will recognize Tom's resume as a fabricator. At an early age, Tom began helping Larry Plank with race prep in the Plank Motorsports shop. At the time, Larry was one of desert racing's rising stars and known for his aggressive driving style. Plank Motorsports produced one of the very first four-link kits for the Ford Ranger, which was featured in our pages. Plank Motorsports also built a bright-yellow F-150 prerunner for Dane Cardone, which was featured in an Off-Road article called "Drool Factor 10," written and photographed by former editor Randall Jachmann. Tragically, Larry Plank died in 2000 when his ultralight aircraft stalled during a flight and fell out of the sky. After Larry's too-soon passing, Tom McKenzie chose to start his own shop, Suspension Innovation Motorsports, or SI. Fellow Plank employee Nestor Berardi also started a fab shop called Newline Products. Although they own separate shops, Tom and Nestor have agreed to share the technology and fabrication jigs they helped develop while working for Plank.
Many would have given up after hearing "I can probably save the doors," but Stu wasn't about to quit. Inspired by the Dane Cardone truck, now better known as Big Bird, Stu regrouped and asked Tom to do whatever he needed to build an F-150 prerunner. "Stu gave me the chance to build the truck of my dreams," Tom acknowledges. "I got to take my time and put all of my best ideas, materials, and techniques into this truck."
After a few years of full-time fab shop ownership, McKenzie decided to restructure his life around building truck after perfect truck. Perfect trucks don't take shape quickly, and perfect trucks don't fund bi-weekly paychecks. Laws, on the other hand, need constant enforcement, and those who do the enforcing definitely get bi-weekly paychecks in addition to benefits and retirement packages. Tom could see that having a steady job as a main source of income would free him up to pursue perfection, one truck at a time. As such, he entered the police academy. A few days a week, Tom hangs up his welding hood, dons a badge and gun, and puts in a full shift.
"I have the best of both worlds," he says. "Running a fab shop full-time is stressful, and being a cop full-time is stressful, so it's good to be able to change up every few days."
Stu's patience and resources combined with Tom's fabricating talents and meticulous nature to produce the wonder truck on these pages. Yes, it's picturesque. It's also one of the very best trucks we've seen to date. It's powerful. It's smooth. It's durable. It's comfortable. It's easy to work on when necessary. Last but not least, it's got a nice set of doors. From unsafe heap to a genuine masterpiece, Stu Ackley's F-150 dreams have come full circle.
The Four-link That Started It AllAs with everything else on this truck, Tom stepped up the rear suspension a notch. He explains: "Most four-link suspensions use a 2-to-1 shock ratio. The shock shaft moves 1 inch for every 2 inches of wheel travel. With a 2-to-1 ratio, the shocks require lots of damping to control the wheels. The higher damping rates mean lots of heat gets generated, which in turn means the shocks run hot. Hot shocks will fade if they get hot enough. I designed this four-link to use a 1.2-to-1 ratio. The shocks move faster than they would at a 2-to-1 ratio, but less damping is required, so the shocks run cooler."
In addition to the cool-running shocks and fade-free shock ratio, the complete rear suspension is mounted to a single crossmember that Tom dubbed "The Gauntlet." The Gauntlet is designed to take all of the force generated by the rear suspension, transferring none of it to the frame. The stock frame is retained but has been kicked up several inches over the rear axle for more compression travel. Check out the super-clean differential breather line routing and the equally sanitary shock mounts.
At the aft end of the trailing arms is a Sandy Cone 9-inch rearend with full-floating hubs, a spool, and CNC brakes. An SI sway bar rides on the housing and controls body roll via two stubs linked to the tops of the trailing arms. "There's only one way to make a four-link work correctly, and that's to use the right geometry," Tom proclaims. "I've designed this four-link with less than 1/16 inch of driveshaft plunge, and the pinion angle changes less than 3 degrees in the 34 inches of rear wheel travel."